1/*
2 * reserved comment block
3 * DO NOT REMOVE OR ALTER!
4 */
5/*
6 * jcomapi.c
7 *
8 * Copyright (C) 1994-1997, Thomas G. Lane.
9 * This file is part of the Independent JPEG Group's software.
10 * For conditions of distribution and use, see the accompanying README file.
11 *
12 * This file contains application interface routines that are used for both
13 * compression and decompression.
14 */
15
16#define JPEG_INTERNALS
17#include "jinclude.h"
18#include "jpeglib.h"
19
20
21/*
22 * Abort processing of a JPEG compression or decompression operation,
23 * but don't destroy the object itself.
24 *
25 * For this, we merely clean up all the nonpermanent memory pools.
26 * Note that temp files (virtual arrays) are not allowed to belong to
27 * the permanent pool, so we will be able to close all temp files here.
28 * Closing a data source or destination, if necessary, is the application's
29 * responsibility.
30 */
31
32GLOBAL(void)
33jpeg_abort (j_common_ptr cinfo)
34{
35 int pool;
36
37 /* Do nothing if called on a not-initialized or destroyed JPEG object. */
38 if (cinfo->mem == NULL)
39 return;
40
41 /* Releasing pools in reverse order might help avoid fragmentation
42 * with some (brain-damaged) malloc libraries.
43 */
44 for (pool = JPOOL_NUMPOOLS-1; pool > JPOOL_PERMANENT; pool--) {
45 (*cinfo->mem->free_pool) (cinfo, pool);
46 }
47
48 /* Reset overall state for possible reuse of object */
49 if (cinfo->is_decompressor) {
50 cinfo->global_state = DSTATE_START;
51 /* Try to keep application from accessing now-deleted marker list.
52 * A bit kludgy to do it here, but this is the most central place.
53 */
54 ((j_decompress_ptr) cinfo)->marker_list = NULL;
55 } else {
56 cinfo->global_state = CSTATE_START;
57 }
58}
59
60
61/*
62 * Destruction of a JPEG object.
63 *
64 * Everything gets deallocated except the master jpeg_compress_struct itself
65 * and the error manager struct. Both of these are supplied by the application
66 * and must be freed, if necessary, by the application. (Often they are on
67 * the stack and so don't need to be freed anyway.)
68 * Closing a data source or destination, if necessary, is the application's
69 * responsibility.
70 */
71
72GLOBAL(void)
73jpeg_destroy (j_common_ptr cinfo)
74{
75 /* We need only tell the memory manager to release everything. */
76 /* NB: mem pointer is NULL if memory mgr failed to initialize. */
77 if (cinfo->mem != NULL)
78 (*cinfo->mem->self_destruct) (cinfo);
79 cinfo->mem = NULL; /* be safe if jpeg_destroy is called twice */
80 cinfo->global_state = 0; /* mark it destroyed */
81}
82
83
84/*
85 * Convenience routines for allocating quantization and Huffman tables.
86 * (Would jutils.c be a more reasonable place to put these?)
87 */
88
89GLOBAL(JQUANT_TBL *)
90jpeg_alloc_quant_table (j_common_ptr cinfo)
91{
92 JQUANT_TBL *tbl;
93
94 tbl = (JQUANT_TBL *)
95 (*cinfo->mem->alloc_small) (cinfo, JPOOL_PERMANENT, SIZEOF(JQUANT_TBL));
96 tbl->sent_table = FALSE; /* make sure this is false in any new table */
97 return tbl;
98}
99
100
101GLOBAL(JHUFF_TBL *)
102jpeg_alloc_huff_table (j_common_ptr cinfo)
103{
104 JHUFF_TBL *tbl;
105
106 tbl = (JHUFF_TBL *)
107 (*cinfo->mem->alloc_small) (cinfo, JPOOL_PERMANENT, SIZEOF(JHUFF_TBL));
108 tbl->sent_table = FALSE; /* make sure this is false in any new table */
109 return tbl;
110}
111